Dog · Canis lupus familiaris · typical adult weight 2.00–80.00 kg
Sulfasalazine is dosed at 10–30 mg/kg PO q8-12h in dogs, per Neiger R, Salavati S. Chapter 53: Motility disorders of the alimentary tract. In: Bruyette DS, ed. Clinical Small Animal Internal Medicine. John Wiley & Sons, Inc.; 2020:563-582. doi:10.1002/9781119501237.ch53; Hall EJ. Chapter 277: Diseases of the large intestine. In: Ettinger SJ, Feldman EC, Côté E, eds. Vol 2. Elsevier Health Sciences; 2017:1565-1592. — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.1230 (2026-08-01).. Sulfasalazine is used in dogs for Colitis, Inflammatory bowel disease / colitis. Routes documented in dogs: PO. A typical adult dog weighs 2.00–80.00 kg. ExoticRx lists 2 cited dose rules for Sulfasalazine in dogs, drawn from published veterinary references. Verify against current literature before clinical use.
US trade names: Azulfidine
| Route | Dose | Frequency | Duration | Indication | Evidence | Source |
|---|---|---|---|---|---|---|
| PO | 10–30 mg/kg | q8-12h | 4-6 weeks then taper | Colitis | Strong |
| Neiger R, Salavati S. Chapter 53: Motility disorders of the alimentary tract. In: Bruyette DS, ed. Clinical Small Animal Internal Medicine. John Wiley & Sons, Inc.; 2020:563-582. doi:10.1002/9781119501237.ch53; Hall EJ. Chapter 277: Diseases of the large intestine. In: Ettinger SJ, Feldman EC, Côté E, eds. Vol 2. Elsevier Health Sciences; 2017:1565-1592. — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.1230 (2026-08-01). |
| PO | 15–30 mg/kgmax 3000 mg total | q8-12h (max 6 g total daily dose) | Initial 4 weeks, then taper | Inflammatory bowel disease / colitis | Strong | Plumb's Veterinary Drug Handbook, 9th Ed, p.1230 (Sulfasalazine, Dosages, DOGS); corroborated by BSAVA Small Animal Formulary 10th Ed Part A p.388 'Dogs: All uses: 15-30 mg/kg p.o. q8-12h, maximum 6 g/day' |
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These ranges are per kg. Enter your dog's weight to get the precise dose and draw-up volume — unit and concentration math done for you.
Cleaved by colonic bacteria to 5-aminosalicylic acid (mesalamine) and sulfapyridine. 5-ASA acts locally to reduce colonic inflammation.
Used for colitis in dogs. KCS (dry eye) risk — monitor Schirmer tear test. Cats: salicylate sensitivity. Folate supplementation recommended. GI upset.
Species-specific contraindications and adverse-reaction reports for dogs may differ from canine / feline reference data — consult the primary citations listed with each rule.
Sulfasalazine dose ranges in dogs, with cited source references: PO 10–30 mg/kg q8-12h; PO 15–30 mg/kg q8-12h (max 6 g total daily dose). Reference ranges from cited sources — verify against current literature before clinical use.
Documented routes for Sulfasalazine in dogs: PO.
Cited course lengths for Sulfasalazine in dogs include: 4-6 weeks then taper; Initial 4 weeks, then taper. Duration depends on the indication — match it to the specific dose rule in the table above.
Sulfasalazine is indicated in dogs for: Colitis, Inflammatory bowel disease / colitis.
These are general warnings for Sulfasalazine across species; consult the dog dosing table above for species-specific guidance. Used for colitis in dogs. KCS (dry eye) risk — monitor Schirmer tear test. Cats: salicylate sensitivity. Folate supplementation recommended. GI upset.
Why a species-specific page? Sulfasalazine pharmacokinetics differ across species: dose ranges, intervals, and route preferences are not interchangeable. Cross-extrapolation from canine doses is unsafe in dogs — the rules above are the citations specific to this species, not generic recommendations.
Sourced from published veterinary references; awaiting credentialed clinical reviewer. See our editorial process. Reference only — not veterinary advice.